[Interventional treatment of biliary stricture]

Biliary stenting is a well-established intervention in pancreatic-biliary disease. Although interventional therapy is an excellent less-invasive method that can improve the quality of life of patients with stricture of the bile duct, inappropriate application can be harmful. The procedure includes the endoscopic as well as percutaneous transhepatic approach. The indications for each procedure depend upon the characteristics of the lesion, and technical feasibility must also be considered. Two types of prosthesis, the plastic tube stent (TS) and expandable metallic stent(EMS), are available. Since the former costs less and has the advantage of removability compared with the latter, it can be used in the treatment of benign strictures and for temporary stenting of resectable malignant strictures. However, the TS has a short patency period because it is likely to become occluded by clogging. In contrast, the EMS has a long patency period due to its large diameter, and multiple stents can be placed in hepatic hilar strictures. Tumor ingrowth is a major late complication of EMS. To maintain patency, other procedures such as radiation, microwave coagulation therapy, and hyperthermia can be considered in combination with EMS, which may contribute to further improvement in survival and quality of life in patients with unresectable malignant biliary strictures. Those procedures should not be performed in patients with benign biliary strictures since the EMS cannot be removed, and the long-term outcome after placement remains to be clarified.